Jar cap



Feb. 1943. H. z. G'oRA 2,311,983

' JAR CAP Filed Jan. 3l, 1941 Patented Feb. Z3, 1943 JAR CAP Henry Z. Gora, Bridgeport, Conn., assignor to Jenkins Bros., New York, N. Y., a corporation of New Jersey Application January 31, 1941, Serial No. 376,895

2 Claims.

This invention relates to closures or caps for jars, particularly Mason fruit jars or the like such as are commonly used by home canners, and yet more particularly to a closure or cap as characterized which is of the one-piece type.

Heretofore, caps for fruit jars of the character under discussion have been provided with a fiaring rim having a rigid seating surface for engagement with a sealing gasket that is backed by a shoulder on the jar. Seating surfaces of this character frequently have irregular seating widths by reason of the nonuniformity of the flaring rim arising from the manner in which these caps are conventionally formed. Furthermore, it has been demonstrated that, particularly when the sealing rings are oi poor quality, they have a tendency to shrink or warp because of temperature and moisture changes, age or the like, with the result that an airtight closure is not maintained due to the rigidity of the cap construction.

It is an object of this invention to provide a cap of the character referred to which overcomes the foregoing difficulties.

More particularly it is an object of this invention to provide a cap of the type characterized which includes automatic compensating means whereby the desired airtight closure is maintained after the initial sealing notwithstanding changes in the gasket.

Another object of this invention is to provide a cap of the type characterized that assures uniformity of seating contact with the gasket.

Another object of this invention is to provide a cap of the type charatcerized with resilient means which may be readily tensioned in making the initial sealing contact and which will assure the maintenance of the sealing contact with the gasket notwithstanding subsequent changes in the gasket.

Another object of this invention is to provide a cap of the type characterized which provides a Contact between the cap and the gasket of minimum radial extent so as to assure a tight closure with the least amount of effort.

Another object of this invention is to provide a cap as last characterized which also includes automatically operating means to assure the maintenance of the airtight closure.

Other objects will appear as the description of the invention proceeds,

The invention is capable of receiving a variety of mechanical expressions, one of which is illustrated on the accompanying drawing, but it is to be expressly understood that the drawing is for purposes of illustration only and is not to be construed as a denitionof the invention, reference benig had to the appended claims for that purpose.

The accompanying drawing illustrates somewhat diagrammatically and on an enlarged scale an embodiment of the present invention in transverse section:

As shown, lil designates a jar of any suitable size, construction and material, such as the conventional Mason fruit jar commonly used by home canners, and provided with the usual shouldered portion I I and helical rib I2 to form a thread for securing a cap thereto. The shoulder I I is adapted to receive the usual jar ring or sealing gasket I 3 of rubber or any other suitable material for effecting an airtight closure as hereinafter explained.

In accordance with the present invention the cap or closure member I4 is made, in one piece, of any suitable material and of such thickness as to provide the necessary rigidity. The peripheral'ange I5 may be knurled as indicated at I6 to facilitate manipulation of the cap, and said ange is provided with a threaded portion I'I for cooperation with the thread I2 on the neck of the jar. Unlike the standard construction of caps of this character, which merge into a flared edge or rim to provide a seating surface for engagement with the gasket I3, the cap of the present invention is provided with a bead I8 which is U-shaped in cross section so as to simulate the corrugation of a bellows. The depth and width of said bead I8 may be varied, depending in part on the thickness and material of which the cap is composed, but taking into consideration such material and thickness the bead I8 should be of suflicient depth and Width so as to possess appreciable resilience for a purpose to be explained. Said bead I8 is disposed between the end of the thread Il and the edge I9, and said edge is preferably made of reenforced construction. To reduce the radial extent of contact between the edge and the gasket and at the same time to maintain a substantially uniform contact throughout the periphery of the cap, said edge is preferably formed by curling the edge of the rim as shown on the drawing so that it will simulate a wire of approximately three sixty-fourths of an inch in diameter. While a circular bead at the rim edge is preferred, this is not essential as the curled edge may be given other cross sections within the contemplation of the present invention.

When a cap constructed in accordance with the present invention is applied to the neck of a jar, after a gasket has been disposed as illustrated, tightening of the cap places the U-shaped bead i8 under an initial tension. The tensioned bead thereafter acts as an automatic compensating means so that if the gasket I3 shrinks or warps with lapse of time the tension in the bead I8 causes the edge I9 to follow the receding gasket and maintain a substantially uniform airtight closure therewith. As the cross-sectional contour of the edge is such las-to establish an approximately line contact between the edge and the gasket, the initial sealing contact may be eiected with a minimum of exertion. Also the contact is substantially uniform throughout its peripheral extent. Thus by firmly tightening the cap against the gasket the resilient bead I8 is placed under an initial tension, and thereafter the airtight closure is automatically maintained ,notwithstanding shrinking or Warpage of the gasket.

It will therefore be perceived that by the presrent invention a one-piece cap of improved con- :struction is provided whereby airtight contact with the gasket is maintained. The sealing contact may be established with minimum eiort, irregularities in the engagement between the cap and the gasket are minimized and, owing to the action of the automatic compensating means provided by the bead I8, uniform air sealing cohtact is thereafter automatically continued.

While the embodiment of the invention illustrated on the drawing has been described With considerable particularity it is to be expressly understood that the invention is not limited thereto, as changes rmay be made in the details of construction, proportion, siZe, etc., Without departing from the spirit of this invention. Reference is therefore to .be had to the appended claims for a definition of the invention.

What is claimed is:

1. A one-piece cap or closure for jars including a peripheral threaded ange having a U-shaped bellows-like corrugation between the threaded portion and the edge of the flange which is compressed by the application of the cap to the jar and which automatically expands to maintain a sealing Contact between the edge thereof and an opposed surface engaged if the latter shrinks or warps.

2. A one-piece cap or closure for jars including a peripheral threaded flange having a curled edge to provide an approximately line contact with an opposed surface and a resilient corrugation between the threaded portion and said curled edge compressed by the engagement of said edge with an opposed surface.

HENRY Z. GORA. 

